The removal of acid gases such as H.sub.2 S, CO.sub.2, and COS and the like from natural and synthetic gases, including hydrogen, to improve their quality is a widely practiced technology employing many different processes based on chemical reactant and physical absorption characteristics of these acid gases with both liquids and solvents. However, one of the most widely used processes employs nitrogenous alcohols (amino alcohols) alone or in combination with one or more chemical reactants or physical absorbents such as sulfolane. These products of the reaction as well as the absorbents of course must be regenerated, freed of the acid gas, and be reused to absorb the acid gases from the natural or synthetic gas in a cyclical process. During regeneration some of the amino alcohols undergo cyclization in the presence of and in reaction with CO.sub.2 to the corresponding oxazolidinone which is difficult to reform into the amino alcohol and release the CO.sub.2 during regeneration. The so-formed cyclic amine which remains unchanged creates a waste product of these unusable heavy materials which must be purged from the system to prevent their build-up.
A recent U.S. Pat. No. 3,658,462 addressed itself to a process to regenerate the amino alcohol in large quantities. However, 1 mol of salt per mole of waste cyclical product processed are formed thus while removing the waste product and regenerating the amino alcohol the salt creates a disposal problem.
In a similar fashion, UK Pat. No. 1,118,687 describes contacting aqueous amino alcohol containing waste streams from acid gas purification processes with sufficient alkaline reacting potassium compound, e.g., KOH, to cause separation into a purified amine rich phase and an aqueous potassium salt containing phase. French Brevet No. 2,382,922 addresses the same problem of regenerating such amino alcohols from acid gas treatment solutions, by heating same in the presence of water at elevated temperature and pressure, e.g., 200.degree.-300.degree. C. and 10-60 atmospheres. U.S. Pat. No. 4,138,468 describes like regeneration of amino alcohols by heating at 140.degree.-200.degree. C. in the presence of a gross stoichiometric excess of water for extended periods of time, generally at elevated pressure.
It would be, therefore, advantageous to have a process for converting the cyclic nirogen compounds (the oxazolidinones) back to their corresponding amino alcohols without the generation of the large solids volume of the conventional base conversions, without the use of elevated pressure or indeed without any separate step of separating and treating oxazolidinone "bottoms".